77923861 has 8 divisors (see below), whose sum is σ = 78975000. Its totient is φ = 76876800.

The previous prime is 77923843. The next prime is 77923873. The reversal of 77923861 is 16832977.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 10929636 + 66994225 = 3306^2 + 8185^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77923861 - 2¹⁷ = 77792789 is a prime.

It is a super-2 number, since 2×77923861² = 12144256226294642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77923831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61765 + ... + 63013.

It is an arithmetic number, because the mean of its divisors is an integer number (9871875).

Almost surely, 2^77923861 is an apocalyptic number.

It is an amenable number.

77923861 is a deficient number, since it is larger than the sum of its proper divisors (1051139).

77923861 is a wasteful number, since it uses less digits than its factorization.

77923861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2039.

The product of its digits is 127008, while the sum is 43.

The square root of 77923861 is about 8827.4492918396. The cubic root of 77923861 is about 427.1267989953.

The spelling of 77923861 in words is "seventy-seven million, nine hundred twenty-three thousand, eight hundred sixty-one".